1. Field of the Invention
The present invention relates to a recording tape cartridge which accommodates a reel on which a recording tape such as a magnetic tape or the like is wound, the recording tape cartridge being loaded at a drive device when in use.
2. Description of the Related Art
Recording tapes such as magnetic tapes and the like are used as recording media for saving data (information) for computers and the like, and for audio use, video use and the like. In order to prevent damage to a recording surface of such a recording tape, due to adherence of dust or the like to the recording surface, finger contact or the like, such a recording tape is employed in a recording tape cartridge. In this recording cartridge, the recording tape is wound onto a reel and the reel is rotatably accommodated in a case formed of resin.
“Single reel cartridges”, in which a recording tape wound onto a single reel is accommodated in a case (these are principally used for back-up of information for computers and the like), two-reel cartridges, which are provided with two reels for winding and unwinding (for example, audio cassettes, video cassettes and the like), and the like are known as recording tape cartridges. When information is to be recorded or replayed with one of these recording tape cartridges, the recording tape cartridge is loaded at a drive device (a recording/replaying device).
In a state in which the recording tape cartridge has been loaded into the drive device and the case has been positioned in the drive device, the recording tape is drawn out of the case. This recording tape is guided along a predetermined tape path and brought close to a recording/replaying head of the drive device. Hence, information is recorded onto the recording tape and/or information that has been recorded on the recording tape is replayed.
Here, as shown in FIGS. 5 and 6, substantially circular arc-shaped reel area ribs 202 are standingly provided in a case 200 (an upper case is omitted from these drawings). The reel area ribs 202 bound a reel area 204 which accommodates a reel (not shown). The reel is urged downward by a spring (not shown). Accordingly, in order to increase rigidity of the case 200 in accordance with pressing force of the spring, the case 200 is made slightly thicker at the reel area 204.
Reference holes 208 and 210 are recessedly provided at two locations in an outer face of a lower case 206, which locations are obverse to a region at an outer side of the reel area 204 (and correspond to inner portions of bosses 205 and 207, which are projectingly provided at an inner face side of the lower case 206). By the reference holes 208 and 210 being insertingly fitted onto pins 214 disposed in a drive device 212, positioning of the case 200 in horizontal directions with respect to a drive device 212 is achieved.
Reference surfaces 208A and 210A, which are recessed from the outer face of the lower case 206, are provided at entry aperture portions of the reference holes 208 and 210, respectively. When the reference holes 208 and 210 are insertingly fitted onto the pins 214, the reference surfaces 208A and 210A abut against pedestal seats 214A provided at the pins 214, and thus positioning of the case 200 in a height direction with respect to the drive device is achieved.
Because the reference surfaces 208A and 210A are recessedly provided in the lower case 206, plate thickness at the reference surfaces 208A and 210A is thinner than at other portions of the lower case 206, such as, for example, portions that form regions peripheral to the reference surfaces 208A and 210A.
As a result, differences in plate thickness between the reference surfaces 208A and 210A and the peripheries of the reference surfaces 208A and 210A are large. As a result, sinking after forming, and flow lines and the like can occur. Moreover, mold transcription is variable, and texture, brightness and the like are irregular, which has an adverse effect on the appearance of the cartridge.